1. Field of the Invention
This invention relates to marking systems and more particularly to transfer tape imprint markers.
2. Prior Art
Imprint markers are commonly used in industry today. A frequent usage is for applying last minute information to product packaging, such as code dating, net weight, price and the like which information cannot conveniently be applied to the packaging at the time of original printing of the packaging.
Such marking devices generally fall into one of three catagories: ink devices such as those using stamp pads or ink rollers; inked tape devices; and transfer tape devices. Transfer tape and ink tape devices can, for the purposes of this invention be considered substantially the same since both rely upon movement of a tape, either called a ribbon or a foil, past an imprint marker station where a marker head having raised indicia thereon is contacted with the tape urging the tape, in the areas of the raised indicia, into contact with the product to be marked.
A common feature to such systems is the necessity of advancing the tape between imprints. This is particularly critical in connection with transfer tape where substantially all of the pigment has been transferred from a carrier strata to the product to be marked in the contact areas of the raised indicia. Should the raised indicia hit the same area a second time no pigment will be transferred.
It has been a common constructional method in the past to use power actuators such as pneumatic cylinders to move both the marking head and the tape drive system. In the context of this invention, a pneumatic cylinder can be either air, air-hydraulic, hydraulic, or in certain limited instances, electrical, including solenoids and trapped wax power members.
Commonly such marking devices have connected the power arm of the pneumatic cylinder to a cam and follower assembly which is operatively connected to the marker head or to a moving anvil in the case of a stationary marker head. A linkage system then connects the cam or follower to the tape drive.
Examples of such prior constructions are to be found in U.S. Pat. No. 3,878,776 utilizing a moving anvil and linkage to a tape drive and U.S. Pat. No. 3,823,664 utilizing a common slide bar having contoured slots in which follower wheels ride, one of which is connected to the moving anvil and the other of which is connected to a tape drive system. A construction similar to U.S. Pat. No. 3,823,664 but where a stationary anvil is utilized in association with a moving marker head with the marker head attached to the slide member through a contoured groove connection is also found in the art.
Finally it has been known to use separate pneumatic actuators for the marking head and for the tape drive. See U.S. Pat. No. 3,881,410.
The use of separate power supplies for the marking and tape portions of the marking device is uneconomical and gives rise to control and timing problems.
The use of linkage systems from a common power arm of a single pneumatic actuator both creates sloppiness within the system and interposes unnecessary parts between the pneumatic actuator and the device that it is actuating, causing problems of space utilization and pivot area wear.
It would, therefore, be an advance in the art to provide an imprint marker which eliminates the prior multi-piece linkage and slide systems while at the same time utilizing only a single pneumatic actuator.